libvirt/src/util/interface.c

272 lines
6.7 KiB
C

/*
* interface.c: interface support functions
*
* Copyright (C) 2010 IBM Corp.
* Copyright (C) 2010 Stefan Berger
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* chgIfaceFlags originated from bridge.c
*
* Author: Stefan Berger <stefanb@us.ibm.com>
*/
#include <config.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#ifdef __linux__
# include <linux/if.h>
#endif
#include "internal.h"
#include "util.h"
#include "interface.h"
#include "virterror_internal.h"
#define ifaceError(code, ...) \
virReportErrorHelper(NULL, VIR_FROM_NET, code, __FILE__, \
__FUNCTION__, __LINE__, __VA_ARGS__)
/*
* chgIfaceFlags: Change flags on an interface
*
* @ifname : name of the interface
* @flagclear : the flags to clear
* @flagset : the flags to set
*
* The new flags of the interface will be calculated as
* flagmask = (~0 ^ flagclear)
* newflags = (curflags & flagmask) | flagset;
*
* Returns 0 on success, errno on failure.
*/
#ifdef __linux__
static int chgIfaceFlags(const char *ifname, short flagclear, short flagset) {
struct ifreq ifr;
int rc = 0;
int flags;
short flagmask = (~0 ^ flagclear);
int fd = socket(PF_PACKET, SOCK_DGRAM, 0);
if (fd < 0)
return errno;
if (virStrncpy(ifr.ifr_name,
ifname, strlen(ifname), sizeof(ifr.ifr_name)) == NULL) {
rc = ENODEV;
goto err_exit;
}
if (ioctl(fd, SIOCGIFFLAGS, &ifr) < 0) {
rc = errno;
goto err_exit;
}
flags = (ifr.ifr_flags & flagmask) | flagset;
if (ifr.ifr_flags != flags) {
ifr.ifr_flags = flags;
if (ioctl(fd, SIOCSIFFLAGS, &ifr) < 0)
rc = errno;
}
err_exit:
close(fd);
return rc;
}
/*
* ifaceCtrl
* @name: name of the interface
* @up: true (1) for up, false (0) for down
*
* Function to control if an interface is activated (up, 1) or not (down, 0)
*
* Returns 0 in case of success or an errno code in case of failure.
*/
int
ifaceCtrl(const char *name, bool up)
{
return chgIfaceFlags(name,
(up) ? 0 : IFF_UP,
(up) ? IFF_UP : 0);
}
#else
int
ifaceCtrl(const char *name ATTRIBUTE_UNUSED, bool up ATTRIBUTE_UNUSED)
{
return ENOSYS;
}
#endif /* __linux__ */
/**
* ifaceCheck
*
* @reportError: whether to report errors or keep silent
* @ifname: Name of the interface
* @macaddr: expected MAC address of the interface; not checked if NULL
* @ifindex: expected index of the interface; not checked if '-1'
*
* Determine whether a given interface is still available. If so,
* it must have the given MAC address and if an interface index is
* passed, it must also match the interface index.
*
* Returns 0 on success, an error code on failure.
* ENODEV : if interface with given name does not exist or its interface
* index is different than the one passed
* EINVAL : if interface name is invalid (too long)
*/
#ifdef __linux__
int
ifaceCheck(bool reportError, const char *ifname,
const unsigned char *macaddr, int ifindex)
{
struct ifreq ifr;
int fd = -1;
int rc = 0;
int idx;
if (macaddr != NULL) {
fd = socket(PF_PACKET, SOCK_DGRAM, 0);
if (fd < 0)
return errno;
if (virStrncpy(ifr.ifr_name,
ifname, strlen(ifname), sizeof(ifr.ifr_name)) == NULL) {
if (reportError)
ifaceError(VIR_ERR_INTERNAL_ERROR,
_("invalid interface name %s"),
ifname);
rc = EINVAL;
goto err_exit;
}
if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
if (reportError)
ifaceError(VIR_ERR_INTERNAL_ERROR,
_("coud not get MAC address of interface %s"),
ifname);
rc = errno;
goto err_exit;
}
if (memcmp(&ifr.ifr_hwaddr.sa_data, macaddr, VIR_MAC_BUFLEN) != 0) {
rc = ENODEV;
goto err_exit;
}
}
if (ifindex != -1) {
rc = ifaceGetIndex(reportError, ifname, &idx);
if (rc == 0 && idx != ifindex)
rc = ENODEV;
}
err_exit:
if (fd >= 0)
close(fd);
return rc;
}
#else
int
ifaceCheck(bool reportError ATTRIBUTE_UNUSED,
const char *ifname ATTRIBUTE_UNUSED,
const unsigned char *macaddr ATTRIBUTE_UNUSED,
int ifindex ATTRIBUTE_UNUSED)
{
return ENOSYS;
}
#endif /* __linux__ */
/**
* ifaceGetIndex
*
* @reportError: whether to report errors or keep silent
* @ifname : Name of the interface whose index is to be found
* @ifindex: Pointer to int where the index will be written into
*
* Get the index of an interface given its name.
*
* Returns 0 on success, an error code on failure.
* ENODEV : if interface with given name does not exist
* EINVAL : if interface name is invalid (too long)
*/
#ifdef __linux__
int
ifaceGetIndex(bool reportError, const char *ifname, int *ifindex)
{
int rc = 0;
struct ifreq ifreq;
int fd = socket(PF_PACKET, SOCK_DGRAM, 0);
if (fd < 0)
return errno;
if (virStrncpy(ifreq.ifr_name, ifname, strlen(ifname),
sizeof(ifreq.ifr_name)) == NULL) {
if (reportError)
ifaceError(VIR_ERR_INTERNAL_ERROR,
_("invalid interface name %s"),
ifname);
rc = EINVAL;
goto err_exit;
}
if (ioctl(fd, SIOCGIFINDEX, &ifreq) >= 0)
*ifindex = ifreq.ifr_ifindex;
else {
if (reportError)
ifaceError(VIR_ERR_INTERNAL_ERROR,
_("interface %s does not exist"),
ifname);
rc = ENODEV;
}
err_exit:
close(fd);
return rc;
}
#else
int
ifaceGetIndex(bool reportError,
const char *ifname ATTRIBUTE_UNUSED,
int *ifindex ATTRIBUTE_UNUSED)
{
if (reportError) {
ifaceError(VIR_ERR_INTERNAL_ERROR, "%s",
_("ifaceGetIndex is not supported on non-linux platforms"));
}
return ENOSYS;
}
#endif /* __linux__ */